Check valve for a discharge air duct

ABSTRACT

Valve (10) comprising a housing (20) with an air inlet (23) mounted at the end of a discharge air duct of a domestic appliance, and with an air outlet (24) communicating with the outside. The valve (10) includes a shoulder (41) sealed to the air inlet (23). A ball (42) is received in the housing (20) and is movable on a guide (43 between first and second positions. When there is no airflow from the duct (60), the ball sealingly engages the shoulder (41) under gravity so as to prevent air from being introduced into the duct from outside through gusts of wind. The shoulder (41) and the ball (42) can be made from an insulating material in order to reduce conductive heat loss in cold weather. When the domestic appliance is operating, the ball (42) moves towards the second position under the discharge airflow in order to evacuate said airflow. As soon as the appliance is stopped, the ball (42) resumes automatically its initial position. The valve (10) may be advantageously mounted on any forced air outlet that can be found on various devices, such as air outlets for driers, for toilet ventilating devices, for air exchangers or kitchen hoods, to replace conventional pivoting valves.

FIELD OF THE INVENTION

The present invention relates to the field of air vents for domesticapparatuses comprising a forced air outlet, as for example dryers,toilet fans, air exchangers, cooker hoods. More precisely, the presentinvention is directed to a valve for a discharge air duct whichparticularly allows to efficaciously reduce the thermic energy losstowards the exterior of the conduits.

BACKGROUND ART

Presently on the market, there are different types of contaminated airvent systems allowing, notably, to discharge contaminated air fromcertain domestic apparatuses towards the outside of buildings. Ingeneral, these systems comprise, at their outlet, a pivoting valveclosing the opening of this outlet such that the penetration of the aircoming from the outside and which is generally caused by wind gusts isreduced. However, these valves are not very efficacious. The airpenetration into the ducts then causes the loss of thermic energy,particularly during cold weather. Moreover, also in cold weather, theheat loss towards the exterior caused by conduction around a vent systemwith a pivoting valve is only slightly reduced.

Therefore, there is a need for an air vent system having the object ofnot only discharging contaminated air towards the exterior, but also tosubstantially reduce the penetration of outside air in the ducts due tothe wind gusts in the ducts, and to reduce the heat loss due toconduction towards the exterior of the ducts during cold weather.

BRIEF DESCRIPTION OF THE INVENTION

An object of the present invention is to provide a valve for a dischargeair duct which substantially reduces the penetration of air in thedischarge air ducts due to wind gusts. This valve may also reduce theheat loss caused by conduction towards the exterior of the duct.

More particularly, the object of the present invention is to provide anair evacuation system comprising a valve having a housing provided witha air outlet and an air inlet fixed at the end of the discharge airduct, which duct may be directly or indirectly connected to the airoutlet duct of a domestic apparatus or any similar apparatus. The valveis characterized in that it comprises, inside the housing, a shoulderhermetically connected to the air inlet of the valve. A ball provided inthe housing is moving between a first and a second position whilefollowing a guide. When no air flow is coming from the duct, the ball isleaning by gravity against the retaining wall, and this, in asubstantially hermetic manner for preventing any penetration of air inthe duct from the outside due to wind gusts.

When the domestic apparatus is on, the ball is moving to the secondposition due to the contaminated air flow. In the second position, theball is remote from the shoulder and is above the level of the firstposition so that it may go back there by gravity when the contaminatedair flow is stopped.

Preferably, the valve also comprises a seat against which the ball isleaning while it is in second position, the seat being provided with atleast one opening to the exterior of the housing. Due to the pressuredifferential between the interior and the exterior of the housing, theball is maintained stable in the second position.

The housing may also be provided with a double wall. This double wallcomprises an interior wall, an outside wall and a hollow passage betweenthe two walls, this passage emerging beside the air outlet which ispreferably provided with a protecting wire netting.

Preferably, the ball and the retaining wall are made with an insulatingmaterial such that the heat inside the duct cannot escape towards theexterior. Moreover, the seat is preferably located in a coverhermetically adapted to the housing.

INDUSTRIAL APPLICATIONS

The air vent being the object of the present invention mayadvantageously apply to any forced air outlet found presently on themarket, such as dryer air outlets, toilet fans, air exchangers or cookerhoods.

DESCRIPTION OF THE DRAWINGS

The features of the present invention will be better understood with thefollowing non restrictive description of a preferred embodiment madewith reference to the appended drawings described hereinafter and inwhich:

FIG. 1 is a cross-sectional view of a valve for a discharge air ductaccording to the present invention and illustrating the ball in thefirst position;

FIG. 2 is the same view as FIG. 1, but illustrates the ball in thesecond position; and

FIG. 3 is an enlargement of the upper part of FIG. 2.

BEST MODE FOR CARRYING OUT THE INVENTION

The following description, given with reference to the appendeddrawings, sets forth the best mode in view of the inventor to carry outthe invention in a commercial environment. However, it is to beunderstood that many modifications may be effected without departingfrom the scope of the invention.

FIGS. 1 to 3 illustrate a preferred embodiment of the valve 10 for adischarge air duct 60 which embodies the features of the presentinvention.

This valve 10 comprises a housing 20 which my be made with a plastic ormetallic material. The housing 20 is provided with an air inlet 23, anair outlet 24, and a collar 25 for connecting the air inlet 23 to an endof the duct 60 such that the contaminated air evacuated from thedomestic apparatus (not illustrated) may penetrate in the valve 10through the air inlet 23. Any other means, such as pliers or screws,allowing to fix the air entry 23 to the duct 60 may also be used. Theair outlet 24, through which the contaminated air is emerging afterpassing through the valve 10, is preferably provided with a removableprotecting wire netting 26 preventing the access in the valve 10 torodents or birds.

It is worth mentioning that the term "domestic apparatus" should beunderstood in its broad sense and that it is possible to use the presentinvention in an institutional, industrial or commercial context. Theword "apparatus" is in fact any apparatus having a forced air outlet onwhich it is suitable to use the present invention. Moreover, in certaincases, it may be advantageous to install an additional duct (notillustrated), connected to the air outlet 24 for directing the air toanother place.

The valve 10 comprises a shoulder 41 located inside the housing 20. Theshoulder 41 is hermetically connected to the air inlet 23 such that allthe air coming from the duct 60 passes therein.

The shoulder 41 is preferably ring-shaped and provided with two specificsections. The first section is cone-shaped for creating a narrowing. Thesecond section is round-shaped for receiving the ball 42 therein. Theround shape of the second section allows the ball 42 to hermeticallylean thereon.

The ball 42 is movable between a first and a second position. While thedomestic apparatus is off, the ball 42 is in the first position where itleans by gravity against the shoulder 41, as illustrated in FIG. 1.

As the apparatus is put on and that a contaminated air flow is propelledtowards the valve 10, the contaminated air penetrates through the airinlet 23. At this moment, due to the contaminated air flow, asillustrated in FIG. 2, the ball 42 is moved towards the second positionwhile following a guide 43. The guide 43 is curved towards the top suchthat the ball 42 is above the level of the first position while it isremote from the shoulder 41. The guide 43 has one of its ends attachedto the box of the shoulder 41. The other end is attached to the interiorsurface of the housing 20. The guide 43, which may be two parallelstems, is made such that it interferes very little with the contaminatedair flow.

When the operation of the apparatus is ended and that the contaminatedair flow stops, the ball 42 goes back by itself to the first positionfor again lean against the shoulder 41. At the same time, the aircontaminated surplus goes back to the apparatus, thereby creating asuction effect on the ball 42, and thus maintaining the ball 42 morefirmly in the first position.

For a maximum reduction of the heat loss towards the exterior, the ball42 and the shoulder 41 are preferably made of an insulating material,such as the polystyrene foam. However, it is not necessary that theseelements be made with an insulating material if the difference oftemperature between the interior and the exterior is always small.

For maintaining the ball 42 in the most possible stable manner in thesecond position under the effect of the contaminated air flow and thuspreventing the movements and the rebounds of the ball 42, the valve 10preferably comprises a seat 51 on which the ball 42 is leaning againstwhile it is in second position 47. This ring-shaped seat 51 is providedwith at least one opening 53 communicating with the exterior of thehousing 20. As illustrated in FIG. 3, the ball 42 may be maintainedstable in the second position because of the pressure differentialcreated between the interior and the exterior of the seat 41, thepressure in the housing 20 being higher than the one inside.

The seat 51 is preferably located in a cover 52 hermetically adaptableto an upper opening of the housing 20. As illustrated in FIGS. 1 to 3,the housing 20 may be provided with a double wall comprising an exteriorwall 27, an interior wall 28 and a passage 30 emerging beside the airoutlet 24. The passage 30 allows the communication of the opening oropenings 53 towards the exterior of the housing 20 beside the air outlet24. It is also possible to provide a passage 30 without a cover 52.However, the cover 52 has the advantage of allowing an easy maintenanceof the interior of the housing 20.

The valve 10 may be installed inside or outside the buildings and thehousing 20 may advantageously be provided with a fastening system (notillustrated), such as screws, allowing to fix the housing to anysurface, more particularly to the exterior wall of the building.

It is also possible to use the valve 10 with a contaminated air flowcoming from the air outlet 24 and then inverting the inlet and theoutlet illustrated in FIGS. 1 to 3. The ball 42 may then be blowntowards the top to the second position under the effect of suchcontaminated air flow, and then allow the passage of the same throughthe valve 10. This is particularly advantageous for apartments where theexterior air outlets are very high and then not very accessible.

Although the best way for carrying out the invention has been describedhereinabove and illustrated in the appended drawings, the invention isnot restricted this only embodiment and by way of a preferred embodimentthereof, may be effected by a person skill in the art without departingfrom the scope or spirit of the invention.

I claim:
 1. A valve for a domestic discharge air duct (60), the valve(10) comprising:a housing (20) provided with an air inlet (23), an airoutlet (24) and a means (25) for connecting the air inlet (23) to an endof the conduit (60); a shoulder (41) located inside the housing (20) andin front of the air inlet (23); a ball (42) movable between a firstposition where the ball (42) is leaning by gravity against the shoulder(41) in a substantially hermetical manner, and a second position wherethe ball (42) is removed from the shoulder (41) and above the firstposition; a guide (43) set inside the housing (20) for guiding the ball(42) between the first and the second position; and a seat (51) on whichthe ball (42) is leaning against in the second position;the valve (10)being characterized in that the ball (42) and the shoulder (41) are madeof an insulating material, the ball (42) being moved towards the secondposition due to a pressure differential created by a passage (30)connecting the top of the seat (51) to an area surrounding the airoutlet (24).
 2. A valve as in claim 1, characterized in that the passage(30) is consisting of a double wall in the housing (20), the double wallcomprising an outside wall (27) and an inside wall (28).
 3. A valve asin claim 1 or 2, characterized in that the air outlet (24) is facing thebottom and is provided with a protecting wire netting (26).